Simultaneous CO2 capture and H2 generation using Fe2O3/Al2O3 and Fe2O3/CuO/Al2O3 as oxygen carriers in single packed bed reactor via chemical looping process

Abstract

The chemical looping concept provided a novel way to achieve carbon separation during the production of energy or substances. In this work, hydrogen generation with inherent CO2 capture in single packed bed reactor via this concept was discussed. Two oxygen carriers, Fe2O3 60 wt.% and Fe2O3 55 wt.%/CuO 5 wt.% supported by Al2O3, were made by ball milling method. First, according to the characteristics of the reduction breakthrough curve, a strict fuel supply strategy was selected to achieve simultaneous CO2 capture and H2 production. Then, in the long term tests using CO as fuel, it was proved that CuO addition improved hydrogen generation with the maximum intensity of 3700 µmol H2·g–1 Fe2O3 compared with Fe-Al of 2300 µmol H2·g–1 Fe2O3. The overall CO2 capture efficiency remained 98%–98.8% over 100 cycles. Moreover, the reactivity of deactivated materials was recovered nearly like that of fresh ones by sintering treatment. Finally, two kinds of complex gases consist of CO, H2, CH4 and CO2 were utilized as fuels to test the feasibility. The results showed all components could be completely converted by Fe-Cu-Al in the reduction stage. The intensity of hydrogen production and the overall CO2 capture efficiency were in the range of 2000–2400 µmol H2·g–1 Fe2O3 and 89%–95%, respectively.